Astral prestige main drain for concrete pools

The main drain of a swimming pool suctions water via the pool floor to ensure a steady circulation current and total recycling of water.
Its other role is to allow your pool water to evacuate when emptying your pool.
More recent models conform to the norm in application, featuring a grill:
- The orifices of the drain should be lesser than 8 mm to avoid the entrapment of pool users fingers
- « antivortex » models which use lateral suction to avoid the formation of whirlpools.